Abstract: In a writing utensil according to the present invention, when a rearward outer cylinder is rotated in either direction, a cam engaging projection, which is integral with the rearward outer cylinder, slides pressingly on either of the respective cam surfaces of first and second sliders. This causes one of the first and second sliders to advance, which in turn causes a first of the first and second refills to project forwardly while the other remains retracted. Similarly, when the rearward outer cylinder is rotated in the opposite direction, the cam engaging projection slides pressingly on the other of the cam surfaces of the first and second sliders. This causes advancement of the other of the sliders, and in turn causes the second of the first and second refills to be projected while the first remains retracted. The construction allows these operations to be smoothly, stably and positively performed.